Question

Draw a landscape image using python coding.

Answer 1

def draw_layers(layers, width, height, color_dict=None):
    # Default color palette
    if color_dict is None:
        color_dict = {'0': (195, 157, 224), '1': (158, 98, 204),
                      '2': (130, 79, 138), '3': (68, 28, 99), '4': (49, 7, 82),
                      '5': (23, 3, 38), '6': (240, 203, 163)}
    else:
        # len(color_dict) should be at least: # of layers +1 (background color)
        if len(color_dict) < len(layers)+1:
            raise ValueError("Num of colors should be bigger than the num of layers")

    # Create image into which the terrain will be drawn
    landscape = Image.new('RGBA', (width, height), color_dict[str(len(color_dict)-1)])
    landscape_draw = ImageDraw.Draw(landscape)
    # Draw the sun
    landscape_draw.ellipse((50, 25, 100, 75), fill=(255, 255, 255, 255))
    # Sample the y values of all x in image
    final_layers = []
    for layer in layers:
        sampled_layer = []
        for i in range(len(layer)-1):
            sampled_layer += [layer[i]]
            # If x difference is greater than 1
            if layer[i+1][0]-layer[i][0] > 1:
                # Linearly sample the y values in the range x_[i+1]-x_[i]
                # This is done by obtaining the equation of the straight
                # line (in the form of y=m*x+n) that connects two consecutive
                # points
                m = float(layer[i+1][1]-layer[i][1])/(layer[i+1][0]-layer[i][0])
                n = layer[i][1]-m*layer[i][0]
                r = lambda x: m*x+n  # straight line
                for j in range(layer[i][0]+1, layer[i+1][0]):  # for all missing x
                    sampled_layer += [[j, r(j)]]  # Sample points
        final_layers += [sampled_layer]

    final_layers_enum = enumerate(final_layers)
    for final_layer in final_layers_enum:
        # traverse all x values in the layer
        for x in range(len(final_layer[1])-1):
            # for each x value draw a line from its y value to the bottom
            landscape_draw.line((final_layer[1][x][0], height-final_layer[1][x][1],
                                 final_layer[1][x][0], height),
                                 color_dict[str(final_layer[0])])

    return landscape